Q. I have a three-year-old Welsh/thoroughbred filly that was diagnosed last fall with liver disease. Our vets expected her to die within the month and told us there wasn’t anything to do.
Luckily, I come from a chiropractic family, and so with chiropractic adjustments and homeopathy my pony is alive and doing well.
I haven’t wormed her since her diagnosis because I know traditional wormers are hard on the liver. I was wondering if you know of a safe and effective natural dewormer. She is kept in a 12-acre field with seven other ponies. I board her and the other horses in her field are chemically dewormed.
Stephanie, Pennsylvania, USA
A. Hi Stephanie,
Thanks for your question. There is much focus on naturally occurring dewormers these days.
The development of resistance to the commercially available dewormers has led scientists to test the effect of numerous plant, fruit, and fungal extracts. Many of these possess antiparasitic properties, and this has been found particularly pronounced for plants containing condensed tannins.
However, the application of these extracts in commercial products is not as straightforward as one might assume. All extracts need to be thoroughly tested for toxicity and safety profiles, which is costly. In addition, horses harbour many different parasite species, and the plant extracts are unlikely to be equally effective against all of them.
The concentration of the suspected active ingredients have turned out to be highly variable from extract to extract, so it is very difficult to ensure that the horse gets the needed dose level. Also, it has been found frequent and repeated treatment is needed to maintain satisfactory efficacy levels.
I have come across several commercial products marketed as natural dewormers over the years. I have many times requested documentation for these claims, but have never seen convincing evidence. Therefore, I am afraid I cannot give you any useful recommendations. My best suggestion would be to test the efficacy of the products you are using. Have your veterinarian perform fecal egg counts before and 14 days after deworming and calculate the percent egg count reduction.
It is worth mentioning that the most used commercial dewormer worldwide is ivermectin by a very large margin.
Ivermectin is per definition a natural dewormer, as it is produced by the naturally occurring fungus Streptomyces avermectilis. Like other dewormers, it has been thoroughly tested for safety and side effects, and there are no signs of liver affection.
Products labelled as “natural” could be just as toxic as anything else. If no safety and toxicity studies have been performed, there is no way to know if it is safe to give such products to your horse.